As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THROUGH 8000' RMU 1 OUT - ELECTRICAL BURNING SMELL IN THE COCKPIT. TROUBLESHOT PER FIM 21-20-00-210-801-A. DETERMINED CAUSE OF SMOKE TO BE THE #1 RMU. PULLED AND OCLLARED #1 RMU CIRCUIT BREAKER. REMOVED AND REPLACED #1 RMU IAW AMM 23-81-01. OPS CHECK GOOD. NO ELECTRICAL BURNING SMELL NOTED. UNCOLLARD AND RESET CIRCUIT BREAKER. OPS CHECK GOOD.